> ## Documentation Index
> Fetch the complete documentation index at: https://docs.omni.co/llms.txt
> Use this file to discover all available pages before exploring further.

# week_start_day - Topics

> Defines the day that weeks start on for queries scoped to the topic.

Defines the day that weeks start on for queries scoped to the topic. This parameter can be set dynamically using a [user attribute](/administration/users/attributes), just like the model-level setting. See the [**Examples**](#dynamic-value-using-user-attributes) section for an example.

For composite topics, Omni uses the day that all member topics agree on. If the member topics don't agree, Omni falls back to the model-level setting and raises a validation warning.

<Note>
  `week_start_day` can also be set at the [model](/modeling/models/week-start-day) and [dimension levels](/modeling/dimensions/parameters/week-start-day). When set at more than one level, the most specific setting is applied: dimension overrides topic, and topic overrides model.
</Note>

## Syntax

```yaml theme={null}
week_start_day: <day_of_week>
```

## Properties

<ParamField path="week_start_day" type="string">
  The day of the week that weeks start on for queries scoped to this topic. Valid values are: `Monday`, `Tuesday`, `Wednesday`, `Thursday`, `Friday`, `Saturday`, `Sunday`.

  Can be set dynamically using [user attributes](/administration/users/attributes).
</ParamField>

## Examples

### Static value

```yaml theme={null}
week_start_day: Sunday
```

### Dynamic value using user attributes

This example assumes your Omni instance has an existing user attribute called `week_start` and that users have been assigned appropriate day values, such as `Sunday` for US users or `Monday` for European users.

```yaml title="Set week start day based on user's region" theme={null}
week_start_day: {{ omni_attributes.week_start }}
```